Replace the SATA_PHY_# by the more readable definitons.

tj: Being routed through libata branch to enable implementation of
    ahci_imx.

Signed-off-by: Richard Zhu <r65037@freescale.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Tejun Heo <tj@kernel.org>